Apparatus for micropositioning an operational member and a workpiece platform

ABSTRACT

Apparatus for micropositioning an operational member and a workpiece platform comprises either a fixed platform or a fixed operational member. In the fixed platform, four arms, each arm comprising a pair of substantially rigid coextensive resilient sections, extend between support posts affixed to the workpiece platform and a suspended operational member to angularly and translationally position the operational member relative to the workpiece platform by varying the extending length of each arm from the support posts by varying the spacing between each pair of resilient sections proximate their midpoints. In the apparatus for aligning the workpiece platform relative to the operational member, the platform has adjustable legs for angularly positioning the platform relative to the operational member and substantially rigid resilient translating legs fixed relative to the operational member, engaging the workpiece platform for translating the platform relative to the operational member by varying the length of each leg extending between its fixed point and the platform.

United States Patent i451 DecQS, 1972 Clark [54] APPARATUS FORMICROPOSITIONING AN OPERATIONAL MEMBER AND A WORKPIECE PLATFORM [72]Inventor: James A. Clark, Mendon, N.Y.

[73] Assignee: Bausch & Lomb Incorporated,

Rochester, N Y.

[221 Filed; nec.s,1969

[21] Appl. No.: 883,044

[52] U.S. Cl ..248/125, 248/274 [5l] Int. Cl ..F16m 13/00 [58] Field ofSearch.....l25/30.5;\5l/l66 TS; 248/44,'

Primary Examiner-William H. Schultz Attorney-Frank C. Parker and BernardD. Bogdon [5 7 ABSTRACT Apparatus for micropositioning an operationalmember and a workpiece platform comprises either a fixed platform or afixed operational member. In the fixed platform, four arms, each armcomprising a pair of substantially rigid coextensive resilient sections,extend between support posts affixed to the workpiece platform and asuspended operational member to angularly and translationally positionthe operational member relative to the workpiece platform by varying theextending length of each arm from the support posts by varying thespacing between each pair of resilient sections proximate theirmidpoints. ln the apparatus for aligning the workpiece platform relativeto the operational member, the platform has adjustable legs forangularly positioning the platform relative to the operational memberand substantially rigid resilient translating legs fixed relative to theoperational member, engaging the workpiece platform for translating theplatform relative to the operational member by varying the length ofeach leg extending between its fixed point and the platform.

11 Claims, 8 Drawing Figures P'ATENEDUE 5 |912 Y 3,704,846

SHEET 1 F 4 JAMES A. CLARK mvENTOR.

BERNARD D. BOGDON TTRNL' PATENEDE 5 i972 3,704,846

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JAMES r A. CLARK INVENTOIL BERNARD D. BOGDON PATENTED UEE 51972 3. 704846 SHEU 3 nr 4 T 74 6 9 e JAMES A. cum( l INVENTOR BERNARD D, 80600"rmx/7 PATENTEU nic 5 |972 SHEU lt F 4 JAMES A. cLARK INVENTOR.

BERNARD D.. BOGDON APPARATUS Fok MicRoPoslTIoNrNo AN OPERATIONAL MEMBERAND A WORKPIECE PLATFORM BACKGROUND OF THE INVENTION lationallymicropositioning an operational member and l aworkpiece platform.

2. Description Of The Prior Art Micropositioning adjustment devices foraccomplishin g accurate alignment are generally expensive to manufacturebecause of tightly held tolerances and frequently require `that extremecare be` used in their handling due to their` generally fragileconstruction and sensitivermechanisms. Frequently numerous sensors arenecessary to monitor alignment during the operation of related machineryto insure that alignment is maintained. It is often the case wherefrequent operational shutdowns are necessary in order to check on theaccuracy of the alignment and to make any necessary adjustments.Sensitive equipment monitoring devices are very costly and generally donot lend themselves to industrial environments involving the massproduction of parts at ve ry great accuracies.

SUMMARY OF THE INVENTION This invention overcomes the `deficiencies of asignificant number of prior art devices and provides a unique method ofadjustment and apparatus for adjustment which is economical tomanufacture andoperate, stable under a great'number of environmentalconditions and reliable to the extend that monitoring devices aregenerally not necessary. The invention provides adjustable lengthsupport arms which are extensible from a fixed base or column to amember such as a workpiece platform of an operating mandrel. Theapparatus provided for by this invention are ideally suited for use, forexample, in the manufacture of optical lenses.

ln the case of the adjustable length support arms extending to carry anoperating mandrel, a plurality of arms may be provided to angularlyposition the mandrel with respect to a fixed base and to translate themandrel for very accurate alignment of, for example, an operating pointon the mandrel and a workpiece supported by the base. Accuracy in theangular and translational alignment of the axis of the operating mandrelis only limited by the quality of the finish on the surfaces from whichmeasurements are taken and the quality of the measuring equipment. Thescope of the invention encompasses adjustable leveling devices forsubstantially transversely aligning a floating workpiece platform foroperational orientation with a fixed mandrel. As a second step,adjustable length arms affixed to a base fixed relative to the operatingmandrel are adjusted to translate the workpiece platform for orientationwith the operational mandrel to thereby provide for very accurateangular and translational alignment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a perspective view of analignment apparatus according to the principles of the present inventionfor aligning an' operating mandrel;

FIG. 2 is an enlarged exploded fragmentary sectional perspective view ofa typical mounting of an adjustable length arm of FIG. 1;

' FIG. 3 is a lateral view of the apparatus of FIG. l illustrating twopositions of angular alignment of the operating mandrel; t

FIG. 4 is a lateral view of the apparatus of FIG. l illustrating twopositions of translational alignment of the operating mandrel;

FIG. 5 is a perspective view of a machine employing an apparatusaccording to the principles of the present invention for aligning aworkpiece platform relative to an operating mandrel; i

FIG. 6 is a sectional plan view ofthe machine of FIG. 5 along the planeof line 6--6 in FIG. 5;

FIG. 7 is a fragmentary lateral view of the workpiece platform and baseof FIG. 6; and

FIG. 8 is a schematic illustration of two translational positions of theworkpiece platform..

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. l illustrates anembodiment according .to the principles of the present inventioncomprising a workbase 10 supporting transversely extending base pillars12 and 14. To support an operating mandrel 16, extending transverselyfrom pillars 12 and 14 are four adjustable length arms 18,20, 22 and 24.Each adjustable length arm comprises two coextensive arm segments 26 and28 having their respective ends rigidly affixed to end extensions 30 and32 which are attached to either base pillar 12 or 14, as the case maybe, and the operating mandrel 16, respectively. The arm segments 26 and28 are affixed to the end extensions 30 and 32 in any suitable manner,such as by means of rivets 34. The operating mandrel 16, for example,carries a rotatable shaft 36 supporting a grinding head 38 forperforming a grinding operation on a lens 40 mounted to a pedestal 42affixed to the base 10.

As in obvious from the illustration in FIG. 1, the operating mandrel `16can be translated and angularly positioned above the lens 40 simply bymanipulation of an adjuster screw 44 which is threadably engaged with,for example, the armsegment 26. The adjuster screw 44 extendstherethrough to bear-against the inside sur-v face of the arm 28proximate the midpoint of the arm segments 26 and 28 to thereby vary, bymanipulation, the spacing X between their inside surfaces to cause theextended length of each of theI arms 18, 20, 22 or 24 to vary from itsfixed mounting at either pillar 12 or 14 to the operating mandrel 16.

It will be appreciated that the spacing X of each arm 18, 20, 22 and24.need not be the same and in practice generally will not be even underconditions of transverse alignment at near equal distances from thepillars 12 and 14 since the elements comprising each arm need not becritically dimensioned and assembled and generally will not be foreconomic reasons, hence structural dimensions will vary. The variationspromote no detrimental consequences, however, because of the uniqueadjustment features.

Although the apparatus disclosed is primarily for micropositioning, itwill be appreciated that for freedom of movement and/or relatively longtranslations from a given point, the arms 18, 20, 22 and 2,4

should be free to rotate at their point of attachment to the pillars l2and 14 and the mandrel 16. Accordingly, as typically shown in FIG. 2,the engagement end 46 lof the end extension 30 is semi-circularly formedand defines aperture 48 for rotatably engaging the base pillar 12. Tothis end a screw 50 passes through an aperture 52 formed in the basepillar 12 and the aperture 48 of the end extension 30 to threadablyengage a rectangular retainer nut 54. The engagement of the endextension 32 is similar.

j In practice, it is frequently desired to transversely dispose theoperating mandrel 16 to the workbase l0. FIG. 3 illustrates, forsimplicity, only twoadjust ble length arms,.for example 18 and 20, insolid line onstruction extending unequal lengths between the base pillar12 and the operating mandrel 16 to angularly dispose the operatingmandrel 16 other than transversely to the workbase l at Position A. Thelength of adjustable arm 20 can either be shortened or lengthened merelyby rotatingy the adjuster screw 44 in either desired direction. ln theillustrated case the length of adjustable arm- 20 isshortened to assumethe broken line position. `By shortening the length of adjustable arm 20the bottom of operating mandrel 16 is thereby repositioned closer tobase pillar 12. In so doing the operating mandrel 16 is transverselydisposed to the workbase at Position B. It is understood that theadjuster screw 44 of each adjustable arm 18, 20, 22 and 24 can beAmanipulated to position the operating mandrel at any selected angle tothe workbase 10.

In a two part operation where both angular disposition and translationof the operating mandrel 16 is required, the procedure followed asreferred to in FIG. 3 is preferably accomplished first. Translationalrepositioning of the operating mandrel 16 without affecting itsangularorientation may be performed by manipulation of the adjusting screws 44of both upper and lower extending arms 18 and 20. This operation is bestillustrated in FIG. 4 where the mandrel 16 may be seen in -two positionsindicated by solid line Position C andbroken line Position D,respectively. It will be appreciated that all arms 18, 20, 22 and 24 canbe operated simultaneously, either manually or automatically, totranslate the operating -mandrel 16 bidirectionally, i.e. alongimaginary X and Y coordinates.

For rigidity of the mandrel 16, four sets of adjustable length arms arepreferred. However, it will be appreciated that certain adjustments canbe accomplished with a fewer number of arms and with the arms affixed tothe base pillars 12 and 14 and the mandrel 16 at other than oppositelydisposed locations. The arm segments 26 and 28 are preferably formed ofresilient materials such as tempered spring steel. Tempered spring steelis rigid to support, for example, the mandrel 16 but flexible to spreadapart and change the extending length of each arm.

The embodiments illustrated in FIGS. l-4 are directed to apparatus forpositioning an operational mandrel relative to a fixed base. It isfrequently neces- Sary as dictated by the related machinery andenvironment to do the opposite and position the base relative t0 themandrel. Accordingly, the embodiment illustrated in FIG. 5 is presented.A base 56 supports a machine head 58 carrying a rotatable shaft 60having an operating tool 62 for performing, for example, a boring orgrinding operation upon a workpiece 64, such as a lens or a lens cell.For operation upon optical elements, it is generally preferred that theaxes of optical elements be aligned with the axes of the operatingtools. To this end, optical elements are mounted upon a work platform 66and positioned to a support block 68 having a substantially circularlyformed cut-out 70 comprising an arc of a circle for supporting agenerally cylindrically shaped optical element 64. The work platform 66is substantially square having chopped corners to form an unequal sidedoctagon and has located proximate each of its four chopped corners fourheight adjusting legs. 72 threadable engaged with the work platform 66and extending therethrough to engage the top surface of the base 56. y

In operation each threaded leg 72 is rotated to vary the amount of itsextention between the underside of the platform 66 and the top surfaceof the base 56 to vary the height of the surface of the platform 66. Totransversely align the work platform 66 with the operating axis of therotating shaft 60 coaxially supporting the operating tool 62, the heightadjusting legs 72 are rotated to adjust the level of the top surface ofthe work platform 66 to achieve with the aid of any suitable measuringinstrument perpendicular alignment between the periphery plane of therotating shaft 60 and the top surface of the work platform 66. A gagesuitable for use in achieving the perpendicular alignment is, forexample, a Brown and Sharpe Electronic Indicator, Model 992 with anelectric indicating head. This invention provides apparatus foraccurately aligning and stabilizing the workpiece platform 66.

To translate the workpiece platform 66 relative to the axis of therotating shaft 60 for alignment of a predetermined point on theworkpiece platform 66 with the axis, there is provided four translatinglegs 74, 76, 78 and 80. One each is disposed at each of the four cornersof the workpiece platform 66, as best seen in FIG. 6. Each of thefourtranslating legs 74, 76, 78 and y80 is supported above the top surfaceof the base 56 by a riser block 82 and is affixed to the base 56 bymeans of a mounting screw 84 passing through one end of each of thetranslating legs and its riser block 82 to threadingly engage the base56. For engaging the other end of each of the translating legs 74, 76,78 and 80, four slots 86 are provided, one each in the lateral side ateach of the corners of the platform 66. Each translating leg 74, 76, 78and 80 is formed of resilient material and is variably extensible fromits fixed mounting at screw 84 by meansof an adjuster 88 extendingthrough an aperture in each of the translating legs proximate theirmidpoint between their fixed mounting at screw 84 and their engagementwith slot 86. The head of the adjuster 88 bears against the top surfaceof the leg and its shaft passes through the leg aperture to threadinglyengage the base 56. Because each of the translating legs 74, 76, 78 and80, as typically shown in FIG. 7 is bowed downward, it is not necessaryduring operation to use any additional means to maintain engagementbetween the ends of the height adjusting legs 72 of the workpieceplatform 66 and the base 56 in order to hold the set leveled position ofthe platform 66.

The translating legs 76 and 78 are primarily for urging the workplatform 66 downward toward the base 56.l For translatiomthe leg 74engages the slot 86 and is affixed therein by means of screws 90 passingthrough the bifurcated corner of the platform 66 and the end of thetranslating leg 74, as best seen in FIG. 7. This en gagement insures adirect translational response when the adjuster 88 of leg 74 is rotated.At the remaining corner of the workpiece plateform 66, the translatingleg 80 engages the slot 86 and is affixed therein by means of asinglescrew 90 passing through the bifurcated section and the leg 80.The single screw attachment provides for pivoting of the vplatform 66when it is translated. 1

lt will be appreciated that for translation the adjusters 88 are rotatedto vary the extensible lengths of the translating legs from their fixedpoints relative to the base 56. The adjusters 88 are rotatable anyamount and slight rotational movement can provide for very accuratealignment of a predetermined point on the workpiece platform 66 with theaxis of the rotating shaft 60.

The schematic of' FIG. 8 illustrates translation of the.

workpiece platform 66 from a solid line Position E to a broken linePosition F accomplished by rotation of the adjusters 88 of thetranslating legs 74 and 80.

Having thoroughly described my invention, as illustrated in thehereinbefore disclosed practical embodiments, I claim the following:

l. An apparatus for positioning in space a member relative to a base,comprising:

at least two adjustable length arms longitudinally extending from themember to means for supporting said adjustable length arms affixed tothe base, each adjustable length arm having two coextensive sections andmeans for engaging said coextensive sections to said member and saidmeans for supporting and further including means for adjustingv disposedbetween each pair of coextensive sections to vary the distance betweensaid pair of coextensive sections and thereby vary the distance betweenthe member and said means for supportmg.

2. The apparatus as defined in claim 1, wherein means for adjusting tovary the distance between the coextensive sections comprises an adjusterthreadably engaged with one of the coextensive sections and disposed forbearing against the other coextensive section.

3. The apparatus as defined in claim l, wherein each coextensive sectionis resilient. j

4. The apparatus as defined in claim l, wherein one arm each is engagedto the member at opposite ends of the member.

5. The apparatus as defined in claim l, further including a thirdadjustable length arm engaging the member and extending substantiallytransversely therefrom to further` means for supporting said thirdadjustable length arm affixed to the base.

6. The apparatus, as defined in claim 5, wherein the third adjustablelength arm comprises two coextensive sections longitudinally extendinglfrom the member to said means for supporting and means for engagingsaid coextensive sections to said member and said means for supporting.

7. The apparatus, as defined in claim 6, further comprising means foradjusting disposed between each pair of coextensive sections to vary thedistance therebetween and thereby vary the distance between the memberand the means for supporting.

8. The apparatus, as defined in claim 7, wherein the means for adjustingdisposed between the coextensive sections comprises an adjusterthreadably engaged with one of the sections and disposed for bearingagainst the other section.

9. An apparatus for positioning in space a member relative to a base,comprising; four arms longitudinally extending from the member to meansforsupporting said arms affixed to the base, each arrn having a pair ofcoextensive sections including adjustable portions and means forengaging said coextensive sections to said member and said means forsupporting and further including means for adjusting disposed betweeneach pair of longitudinally extending sections to vary the distancebetween said pair of coextensive sections and thereby vary the distancebetween the member and said means for supporting.

10. The apparatus as defined in claim 9, wherein the coextensivesections are resilient.

11. The apparatus as defined in claim 10, wherein the means to vary thedistance between the sections comprises an adjuster threadably engagedwith one of the sections and disposed for bearing against the othersection.

1. An apparatus for positioning in space a member relative to a base,comprising: at least two adjustable length arms longitudinally extendingfrom the member to means for supporting said adjustable length armsaffixed to the base, each adjustable length arm having two coextensivesections and means for engaging said coextensive sections to said memberand said means for supporting and further including means for adjustingdisposed between each pair of coextensive sections to vary the distancebetween said pair of coextensive sections and thereby vary the distancebetween the member and said means for supporting.
 2. The apparatus asdefined in claim 1, wherein means for adjusting to vary the distancebetween the coextensive sections comprises an adjuster threadablyengaged with one of the coextensive sections and disposed for bearingagainst the other coextensive section.
 3. The apparatus as defined inclaim 1, wherein each coextensive section is resilient.
 4. The apparatusas defined in claim 1, wherein one arm each is engaged to the member atopposite ends of the member.
 5. The apparatus as defined in claim 1,further including a third adjustable length arm engaging the member andextending substantially transversely therefrom to further means forsupporting said third adjustable length arm affixed to the base.
 6. Theapparatus, as defined in claim 5, wherein the third adjustable lengtharm comprises two coextensive sections longitudinally extending from themember to said means for supporting and means for engaging saidcoextensive sections to said member and said means for supporting. 7.The apparatus, as defined in claim 6, further comprising means foradjusting disposed between each pair of coextensive sections to vary thedistance therebetween and thereby vary the distance between the memberand the means for supporting.
 8. The apparatus, as defined in claim 7,wherein the means for adjusting disposed between the coextensivesections comprises an adjuster threadably engaged with one of thesections and disposed for bearing against the other section.
 9. Anapparatus for positioning in space a member relative to a base,comprising; four arms longitudinally extending from the member to meansfor supporting said arms affixed to the base, each arm having a pair ofcoextensive sections including adjustable portions and means forengaging said coextensive sections to said member and said means forsupporting and further including means for adjusting disposed betweeneach pair of longitudinally extending sections to vary the distancebetween said pair of coextensive sections and thereby vary the distancebetween the member and said means for supporting.
 10. The apparatus asdefined in claim 9, wherein the coextensive sections are resilient. 11.The apparatus as defined in claim 10, wherein the means to vary thedistance between the sections comprises an adjuster threadably engagedwith one of the sections and disposed for bearing against the othersection.